HeatofFusionofIceLab

• In this lab, you are trying to find the amount of heat (latent heat) needed to bring a given amount of ice into the liquid phase or Heat of Fusion of Ice (H.F.I.). Since the easiest way to measure heat flow is by temperature change, it is difficult to get an accurate temperature reading from the thermometer on a piece of ice.

• Therefore, we will use a common trick. Instead of watching what is happening with the ice, we will immerse the ice into a bath of water and follow the temperature of water instead.

• Since the 1st Law of Thermodynamics (you know it better as Law of Conservation of Energy) states, Energy is neither created nor destroyed in a physical process or chemical reaction, and the 2nd Law of Thermodynamics states, heat flows from high temperature body to lower temperature body until the temperatures are the same, then the energy lost by the water (decreasing temperature) is gained by the ice in melting (Heat of Fusion of Ice). Of course, there is a big assumption here, that no energy/heat is lost to the surroundings.

• As you know from the chapter on Energy, we always define the system of a heat equation so that we can determine the sign of the energy (deltaH or q).
  • Remember, "-" deltaH indicates that the system is losing (or giving off) heat and "+" deltaH indicates that the system is absorbing or gaining heat.
• So, when you find the amount of heat lost by the water system ("+' deltaH), that heat will be a "-" deltaH for the ice system. Therefore, you must let everybody know this so you must make a statement between the two calculations to state this. For example,
  • Since the water lost $$$calories" of heat (-deltaH), then the ice will gain heat thereby, the deltaH will be "+"$$$calories in the ice equation.

Before giving you the steps to do this calculations, please remember that these calculations are for transferring of heat between two bodies. This is totally different then when you are simply adding heat to a piece of ice and it is changing phase into the liquid then gas phase. To calculate this heat requirement, you must add the sensible and latent heats as discussed in HeatingCurveNotes.

Data Table:

• Volume of Heated water (ml):

• Temperature of Heated water (degree C):

• Final Temperature of water (degree C):

• Final Volume of water (ml):

• Density of hot water from Handbook of Chemistry & Physics(g/ml):

• Density of water at final temperature from above book (g/ml):

Calculations (will use density of water = 1.00g/ml)

1. Calculate volume of Ice that melted into water (ml):

2. Calculate the mass of heated water (g):

3. Calculate the heat lost (in cals) by the water, deltaH =(m)(c)(deltaT)

4. State what causes the sign change of the heat lost by water and gained by ice.

5. Calculate the Heat of Fusion of Ice by deltaH = (m)(H.F.I.)

6. Calculate the Percent error knowing that the true value is 79.7cal/g.